Method of preparing fur for felting



Patented May 1, 1945 METHOD OF PREPARING FUR FOR FELTING Alfred E. Hodshon, Bucks .County, and Harold H. Tucker, Montgomery County, Pa., assignors to John B. Stetson Company, Philadelphia, Pa., a corporation of Pennsylvania No Drawing.

Application September 4, Serial No. 457,314

4 Claims. (Cl. 8-112) This invention relates to an improvement in the treatment of fur to prepare it for felting into hats. The invention more particularly relates to a carroting and drying process by which'rabbit, hare, beaver and similar types of fur are treated.

In accordance with present processes, the fur.

while stfll on the skins, has the carrot brushed upon it. The skins may then be stacked, fur against fur, in piles and allowed to stand for the carrot to work in, after which the skins are dried in hot air, or the skins may be dried directly in hot air without stacking. In either case after drying it is necessary to allow the skin to absorb moisture so that it will be pliable enough to run through the cutting machine.

The carroting solutions vary considerably, but the drying methods now in use all employ hot air as a drying medium. The usual drying temperatures employed for non-mercurial carrots vary from 80 Fahrenheit to 180 Fahrenheit, while for mercurial carrots the temperature used may be as high as 250 Fahrenheit. A proper combination of carroting method and drying process will produce a fur fiber that will not deteriorate after along period of time, will wet down quickly. will felt rapidly and will produce a strong, tight, even felt that can be dyed properly.

Fur still on the skin and after carroting has heretofore been dried in chambers or ovens, causing the entirelength of the fiber to be subjected to a uniform temperature, which resulted in a deterioration of the uncarroted'portion of the fiber due to the effect of this heat. Moreover, in oven drying, because of the heat, steam and chemical vapors develop which act upon the fur fiber along its entire length and also delay. the drying action. The steam and chemical vapors may be withdrawn with exhaust fans, but the fans also withdraw the heat.

Although the treatment of the 'fur in accordance with this invention is particularly adaptable where non-mercuric carrots are used and where the carrot is volatile and gives its maximum carroting effect during the time of its application and drying, it is also useful where mercuric carrots are used, and in use with these the aging or storing time can be materially reduced.

Although no completely satisfactory theory of to the base of the fibers.

carrots have been, developed. It is believed that the felting rate of a fur is determined by the 1 character of the carroted portion of the fiber and that the quality of the felt depends chiefly upon the untreated portion of the fiber. Moreover, it is believed that the best possible quality of felt would be obtained from fibers which have been carroted at one end (/3 to Va of the fiber length), while the uncarroted portion of the fiber was preserved in as near its original state as possible. In order to attain this ideal condition the carroting and drying would have to be regulated so as to produce the least possible chem ical or physical change in the uncarroted portion of the fiber. In other words, the uncarroted portion of the fiber should be kept as free as possible from the deteriorating effects of heat, light, steam or chemical agents.

Applicants have discovered that this can be done effectively by the use of the radiant heat of infra-red lamps for drying, in which the lamp is directed only toward the fur side of the skin. The-drying efiect is greatest on the tips of the fibers, which is the place where the carroting solution has been applied. The fur is so dense as to substantially prevent penetration of the rays Because of this, the light and heat effects on the base portion of the fibers are at a minimum.

It has been discovered that with the use of infra-red rays for drying temperatures as high from the fur so that the drying is not delayed and the vapors do not act upon portion of the fiber.

The higher temperature 200 to 350 Fahrenheit used in infra-red drying causes a rapid removal of vapor from the carrotedv ends of the fibers, which prevents the diffusion of the carroting solution into the base portion of the fiber.

In drying by former methods the skin became so shrunken and wrinkled in order to dry the fur, that the skin had to be remoistened to pass it through the cutting machines in order to out the fur oil. An unexpected result of this invention is that the skin itself is not dried so that it shrinks or wrinkles in drying the fur, and no remoistening is required for cutting.

According to this invention the skins are carroted in the usual manner, except that about onefourth less carrot is applied than usual. The

the uncarroted skins are placed on an endless conveyor, fur up,

and passed into a dryer where they are subjected to the action of infra-red rays directed on the fur side only, from 250 watt lamps arranged in a group to evenly cover the fur on the skins as they pass by. These 250 watt lamps are standard Westinghouse R40 (infra-red) lamps and are normally operated at a filament temperature of 2500 Kelvin. This characterizes the radiation from the lamps and the range of infra-red given by these lamps is from 65003 to 15,000 A. These limits of radiation include the range of penetrat-.

ing rays which is from 6500 A to 14,000 A. The short wave lengths of this range-are visible. It is these penetrating infra-red rays which are believed to be the effective agent in our process. The distance of the lamps from the fur is varied from 12 to 24 inches, depending on the type of skin and the amount of carrot applied. Care must be taken not to have the fur close enough to the lamps so that it becomes singed or damaged. For

English coney skins a distance of 12 inches from the lamps heated the tips of the fur to about 340 Fahrenheit and produced satisfactory results with a drying time of 7 minutes. Exhaust fans withdraw all vapors from the dryer. The rays are of a length within the near-visible infra-red portion of the spectrum.

While this invention is capable of being carried out in many difierent ways, for the purpose of illustration the above example is given.

It has been discovered that the fur so treated is completely carroted even with this less amount of carrot, and it is believed that the infra-red rays not only enhance or add to the effectiveness of the carrot used, but that they create in the fibers themselves substances that forward the carroting process, probably by the creation of additional carroting substances, and this discovery is an unexpected result fiowing from the use of these rays.

Fur so carroted and dried felts rapidly and the felt possesses body as well as tightness and the fur is not burned at the high drying temperature and is not turned yellow.

This drying process allows for the maintenance or uniform conditions of heat and humidity. In

drying by this process, fur will felt when carrots are used which will not work under existent systems. The fur is completely driedwithout hardening the skin, thus eliminating rewetting before cutting and carrot is saved.

It will be seen that the novel features of this invention comprise using less added carrot and drying the fur by subjecting it to the action of infra-red rays. No claim is made to the heating unit or to drying generally other articles with infra-red rays. However, claim is made to the use of infra-red rays to supplement the carrot used and at the same time to dry the fur. The supplementing of the carrot on the fur, by the use of the rays may occur before the carrot is applied or while the carrot used, or added. is still working on the fur and before it has dried. Applicants are not aware of any other use of the action of infra-red rays to both supplement the carrot used, and to uniformly dry the fur at the same time.

It is not known definitely that the above explanation is the correct one for the unexpected result of obtaining a completely carroted fur with less than the generally required amount of carrot to properly felt, after drying with infra-red rays, and the real reason may later be discovered.

It was found that the quality of felt produced from fur. that had been carroted and dried using infra-red rays was superior to that which had been dried by the usual methods. This we believe is due to the fact that in infra-red drying the base of the fur fiber remains substantially free from the carrot, because the quick drying with exuded steam and vapors removed prevents the spread of the carrot to the base of the fur, and the absence of steaming does likewise. Thus, the fur fibers are well carroted at their tips and free from chemical and extreme infra-red ray treatment at their bases, and this condition of the fiber, it has been discovered, produces quick felting and a firm, close felt. It also produces felt that will hold together well, that will take and hold dye, and that will be soft as well as having firmness and body.

It has been definitely found that the action of infra-red rays on fur is different from that of oven lightless heat of the same temperature and with the same time of exposure. coveries of this invention, tests were conducted revealing that infra-red .ray treatment at 338 Fahrenheit for ten minutes increased the feltin rate of fur, while oven lightless heat for a like time and temperature decreased it. Whatever the reasons responsible for the superior results obtained by this invention, such reasons are of secondary importance. The directions herein given will enable one to practice the invention and obtain the advantages thereof.

What is claimed as new and is desired to be secured by Letters Patent is:

1. In the process of preparing fur for felting the step which consists in partially carroting the fur by exposing the fur to radiation, the major portion of the radiation being of the infra-red wave length within the range of from 6500 A to 14,000 A .to partially carrot the fur.

2. The process of preparing fur for felting comprising partially carroting the fur with carrotin solution and subjecting the same to radiation, the major portion of which is in the infra-red portion of the spectrum within the range of from 6500 A to 14,000 A to completely carrot the same.

3. The process of preparing fur for felting which comprises subjecting fur which has been previously partially carroted with carroting solution while still on the skin to radiation, the major portion of which is in the infra-red portion of the sepctrum within the range of from 6500 A to 14,000 A to completely carrot and dry the fur.

4. The process of preparing fur for felting comprising applying carrot solution to the tips of the fur fibers while still on the skin to partially carrot the fur and exposing the same to radiant heat rays having wave lengths within the near visible infra-red portion of the spectrum within the range of from 6500 A to 14,000 A with the fur toward the rays at a temperature less than the singeing temperature of the fur to completely carrot the fur tips before the carrot solution After the dis- 

